Sawmill set-works



' (No'ModeL) 5 Sheets-Sheet 1.

' H. MODERMOTT.

SAWMILL SET WORKS.

Patented July 21, 1896-.

Fish 1-.

(No Model.) 5 Sheets-Sheet 2.-

H. MQDBRMO-TT SAWMILL SET WORKS.

No. 564,530. Patented July 21, 1896.

v(N ModeL) 5 Sheets-Sheet 3 H. MoDERMOTT. SAWMILL SET WORKS.

No. 564,530. Patented July 21, 1896.

(No Model.) 5 Sheets-Sheet 4.

H. McDERMOTT. SAWMILL SET WORKS.

No. 564,530. Patented July 21, 1896.

(No Model.)

- H. MQDERMOTT. beets Sheet SAWMILL SET WORKS. No. 564,530. PatentedJuly 21, 1896;

FIG. ll-

I 0. ms Nonans PETERS co. PHnTuuTHo. WASHINGTON, a

UNITED STATES PATENT ()FEIcE.

HENRY MCDERMOTT, OF MARINETTE, WVISCONSIN.

SAWMILL SET-WORKS.

SPECIFICATION forming part of Letters Patent No. 564,530, da.ted July21, 1896.

Application filed November 1,1895. Serial No- 567,647. (No model.)

To all whom it may concern.-

Be it known that l, HENRY McDERMoTT, a citizen of the United States,residing at Marinette, in the county of Marinette and State ofWisconsin, have invented certain new and useful Improvements in SawmillSet-\Vorks; and I do hereby declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

My invention relates to improvements in set-works for sawmill-carriages,and it is intended to provide an improved means of accurately adjustingthe set-works so that boards of a uniform thickness may be cut and sothat the thickness of the boards may be regulated within extremelynarrow limits; and the said invention is also intended to provideagainst accidental stripping of the ratchetwheels ordinarily used insawmillset-works organizations, and for other purposes that will behereinafter more fully described.

Reference is had to the accompanying drawings, in which the same partsare indicated by the same letters throughout the several views.

Figure 1 represents my improved set-works, partly in elevation andpartly in section, the section being along the line 1 1 of Fig. 2 andlooking in the direction of the arrows. Fig. 2 represents an end view ofthe set-works as seen from the left of Fig. 1. Fig. 3 represents asectionalong the line 3 3 of Fig. 2 and looking to the right or in thedirection of the arrows. Fig. 4 represents a similar view to that shownin Fig. 1, but shows a modified form of mechanism for operatingthe-ratchetwheels, in which the set-works are operated by each stroke ofthe hand-lever. Fig. 5 represents a plan view of the device shown inFig. 4. Fig. 6 represents a detail view showing one of theratchet-wheels with the pawls in operation. Fig. 7 represents inperspective one of the eccentric-pins on which the pawls are journaled,whereby a nicer adjustment may be given to the said pawls. Fig.

8 is a detail view showing one of the sliding stop-pins used tolimitthemotion of the handlever for operating the set-works, showing a sectionalong the line 8 of Fig. 4. Fig. 9 is a view similar to that shown inFig. 1, but represents a modification in which two countershafts areused and each stroke of the handlever moves the set-works. Fig. 10 is adetail view showing the ratchet-wheels and pawls as detached from therest of the mechanism shown in Fig. 9. Fig. 11 represents a plan view ofthe device shown in Figs. 9 and 10. Fig. 12 represents a sectional viewsimilar to that shown in Figs. 1, 4, and 9 and represents a furthermodification of the ratchet-and-pawl arrangement and the means foroperating the same and shows the motion given by a single ratchet-wheel;and Fig. 13 represents a section along the line 13 13 of Fig. 12 andlooking to the right.

Arepresents the frame of the saWmill-carriage, provided with the usualhead-blocks A, in which slide the knees B, provided with racks Z),gearing in the pinion c on the set shaft 0, by the motion of which shaftthe knees are moved in or out toward or away from the saw-line. (Notshown.) This shaft 0 carries a gear-wheel O and a plurality ofcoil-springs G which are wound up as the knees are moved toward thesaw-line, and are under sufficient tension to withdraw the knees to therear automatically when it is desired to insert a fresh log, at whichtime the set-works mechanism is thrown out of operation, as will behereinafter more fully described.

D represents a pinion meshing in the gearwheel 0 and revolubly mountedupon the countershat't E. The hub D of this pinion is provided'with oneof the parts D of a clutch-coupling, the other part, D of which isfeathered on the counter-shaft E and is held in engagement with thefirst part by a spring D as shown in Fig. 5, or bya spring, such as D,(shown in Fig. 2,) which in this case bears upon the uncoupling-lever Dor the said parts maybe held in engagement in any other way desired.

It will be obvious that the part D of the coupling may be set againstthe back of the pinion D or made integral therewith if pre ferred, butfor convenience in manufacture it will ordinarily be preferable tomanufacture the gear-wheel D and the said part D as separate pieces,which may be rigidly connected to each other in any convenient Way. Bymeans of this clutch-coupling, the motion of the counter-shaft Eimparted thereto by the ratchet-Wheels and the pawls operating the sameis transmitted to the pinion D, loose on said counter-shaft, and thus tothe set shaft 0.

It will be understood that in set-works of the ordinary constructionseveral heavy receding-springs, such as those shown at C are placed onthe set shaft C, connected and coiled in such a manner that as theset-works are operated and the knees advance these springs are wound upor increased in tension. As the ratchet mechanism is adapted only toadvance the knees, the purpose of these coilsprings is to recede theknees preparatory to taking 011 a new log. These coil or recedingsprings and the ratchet-pawls act constantly in opposition to eachother, and the said clutch-coupling is for the purpose of disengagingthe set shaft from the holding effect of the said pawls and to allow thesame to withdraw the said knees without rendering it necessary to easedown the set-works mechanism or to touch the pawls. In the usualconstruction of set-works organization the break between the set shaftand the ratchetand-pawl arrangement is made by tripping the pawls fromtheir engagement with the ratchet, and in case of careless handling oraccident allowing the pawls to drop while the knees are receding, ortaking the strain imposed by loading a heavy log on the set-worksmechanism, the ratchet wheel or wheels are liable to be stripped, and asthese wheels are very expensive and difficult to make, and the value ofthe entire output of the mill depends in a large measure on the accuracyof the said ratchet wheels, the preservation of these wheels fromaccident becomes a matter of considerable importance.

It will be seen that in the herein-described invention both theratchet-wheels and the pawls are thrown out of the train of mechanismtogether, removing the field of possible accident to the clutch, whichis of cheaper and stronger construction. Independent means for holdingthe counter-shaft, such as an auxiliary instantaneous clutch, well knownin the art, may be adopted, if desired.

In the two forms of device shown in Figs. 1 to 5, two ratchet-wheels Fand F are employed, both of which are keyed fast on the counter-shaft Eand are engaged by the series of differential pawls M, mounted on thesegmental pawlcarriers K and K and operated by the hand-lever II, whichis forked, as at H, and slides into guides k in the said segment K,where it may be either held loosely, as shown in Figs. 1 and at, orbolted in place, as shown at h in Figs. 9 and 12. These segments K and Kare journaled 011 the countershaft E, and are oscillated by means of thehand-lever H, already referred to.

The pawls M are each set the one in advance of the one next behind it.Thus if there are four pawls, as shown, when the first pawl engages atooth of the ratchetwheel the second pawl laps a quarter of the nexttooth, the third pawl laps a half of the next tooth, and the fourth pawllaps threequarters of the next tooth.

here a less number of pawls are used, each pawl would lap more on thetooth, and where a greater number of pawls are used each pawl would lapless, the position of each pawl being indicated by the distance betweenthe ratchet-teeth divided by the number of pawls used. Since these pawlsare apt to wear, in order to provide for a nice adjustment, the saidpawls are preferably j ournaled 011 eccentric-pins N, having theeccentric portion it somewhat larger than the end bearings or, while theprojecting end of the said pin is made angular, as at M, (see Fig. 7,)to engage a wrench, by means of which the said pin N may be turned. Thevarious pins N are set at the desired position by means of the setscrews mi. (See Fig. 6.)

In order to provide for each pawl continu ously bearing on the face ofthe ratchetwheel, alternate pawls are provided with projecting lugs m,projecting to the rear of the said pawl, between which and the adjacentpawl a spring m is interposed, as shown most clearly in Fig. 6, and thisspring tends to keep both of the adjacent pawls continuously bearing onthe ratchet-teeth. It will be seen that by this arrangement of pawls onepawl will always be readyto enter into engagement with one of the teethof the ratchet-wheel, with little or no lost motion, and thus anexceedingly nice adjustment can be had.

In practice it is found desirable to make the ratchet-teeth of at leastone-quarter inch, and without the multiple pawls no adjustment of lessthan one-quarter inch could be made. For instance, by applying all theoperations through a medium of a countershaft and reducing any errorswhich might possibly occur in the same two or three times by spur-gearconnections on the main set shaft, (the ratchet-wheel being divided intoquarter-inch teeth, with four pawls, as described), then reduced asabove, by actual working of the set-works apparatus, about one hundredclicks of the pawls are given to a one-inch board, and if a tooth isslipped by any means the lost motion is one one-hundredth of an inch inthe knees, which motion is too insignificant to be considered.

With set-works as now ordinarily constructed the closest work claimed isfrom one-sixteenth to one thirty-second of an inch for every click ofthe pawls, involving an error of a like distance in the motion of theknee when one of the pawls skips atooth.

1? represents a metal plate or frame, the rear end P of which is in theform of a quadrant struck with the same center as the counter-shaft E,which quadrant is perforated with aplurality of holes 19, adapted toreceive one or more stops. These stops may be simple pins put into theseholes and shifted from one hole to the other when desired; but I preferthe construction of stop shown in Fig. 8

IIO

and indicated in Fig. 4, where p represents a stout pin fitting in thechamber P in the face of the quadrant P, to the back of which pin isattached a guide-shank 19, passing through the hole in the quadrant Pand terminatin g in a suitable head 19 which, for convenience ofmanufacture, would preferably be in the form of a nut or washer or both.These pins are preferably permanently mounted in the quadrant P, and arepressed back out of the travel of the arm it", carried by the lever I-I,all except the pin that is intended to be used as a stop, which pinserves to limit the travel of the hand-lever, and thus of the ratchetwheel or wheels.

In addition to the adjustment afforded by these pins 19 as shown in Fig.4, a more refined adjustment is given on the opposite side of the leverH by means of the adjustable stop Q. (shown in Figs. 1 and 4) or Q, asshown in Figs. 9 and 12. I prefer, however, the form of stop shown inFigs. 1 and 4', in which Q represents a cam-plate having the camsurfaceq and the teeth (1 and the handle q. In these teeth the pawl R engages,and the said pawl is held in engagement by means of the spring B. Bythrowing the handle q in the direction of the arrow, (see Fig. 4,) theout ward travel of the handle-lever H, or of the arm it carried thereby,may be shortened by any desired small fraction of an inch, and theoutward travel of the knees may be lessened by a corresponding amount.The travel of the knees will then depend directly upon the length of thestroke, or rather the angular distance through which the hand-lever H isturned. Now as the movement of the lever and knees must include not onlythe thickness of board desired, but also the kerf of the saw, both ofwhich elements are variable, it

becomes desirable to make the governing stroke of the lever variable,and to adjust this stroke so that extremely small variations may beprovided for. To this end the pins 19 are placed according to thestandard thickness of board desired, and the adjustable stop Q or Q isadjusted according to the variations in the saw-kerf, and also accordingto the slight variations from standard thickness of boards that may bedesirable in certain classes of lumber. It will be noticed that this adjustability of the stop Q is of especial importance in connection withthe differential-pawl system, as, if one pawl only were used and thestops were set so that a stroke of the lever would give an advance ofthe knees for an inch board plus the saw-kerf, and a thinner saw wereput on the mill, each stroke of the lever would still advance the kneesthe same amount as before, and the difference in the decreased thicknessof the saw would be lost to the manufacturer, as this would only add tothe thickness of the lumber. Now, if the adjustable stop were set out tocompensate for this, it would be of no avail, as on the return stroke ofthe lever the pawl would fail to catch on the tooth of the ratchet bythe amount the stop had been set out, and on'the next stroke the pawlwould fail to catch until the next tooth was reached, the knees wouldnot be advanced the requisite amount, and the value of the board wouldbe lessened on account of being too thin; but with my system of multiplepawls in combination with the adjustable stop, in the exigency above setforth, the second pawl would come into play, on the next stroke thethird, on the next the fourth,

being held stationary by standard K and the pawls imparting motion tothe knees only on moving the hand-lever H in one direction. This, undercertain conditions, is desirable, as the sawyer can go ahead as soon ashe sees the setter throw the hand-lever down, the return motion of thehand-lever, or lifting the same up, being done at the leisure of thesetter, while the sawmill-carriage is in motion and the saw inoperation.

In the device shown in Figs. 4, 5, and 6 the hand-lever operates both onthe down and the up stroke, the segment K being provided with an arm Kconnected by the link S to the crank S, j ournaled on the rock-shaft sin the bearing T, which may also be part of one of the set-shaftbearings, as shown in Fig. 4, if preferred. This crank is provided witha cross-head s, to which both the link S and the link S are pivotallyconnected. The latter link is pivotally connected at its opposite end tothe movable segment K, which in this case is also pivoted on thecounter-shaft E, and it will be seen by an inspection of Fig. 4 that ifthe hand-lever H be moved in the direction of the arrow the segment Kwill turn the ratchet-wheel F, while the segment K will slide back overthe teeth of the ratchet-wheel F, which ratchet-wheel is behind andhidden by the ratchet-wheel F in Fig. 4, but is shown in Fig. 5. Themotion of the hand-lever II in the opposite direction will cause thesegment K to turn the ratchetwheel F, while the segment K will slideover In the form of device shown in Figs. 9 to 11 there are twocounter-shafts E and E, carryin g two ratchet-wheels F and F operated bythe upper segment K and the lower segment K connected together by thelink K pivoted at one end to the arm K and at the other to the segment KThese two counter-shafts carry equal-sized gear-wheels e and e, and thecounter-shaft E transmits its motion to the set shaft 0 in the manneralready described with reference to Figs. 1 to 5.

By an inspection of Fig. 10 it will be seen that the reciprocatingmotion of the handlever II will give a continuous rotary motion to thecounter-shaft E, and thence to the set shaft O, and thus the nicety ofadjustment claimed for the construction shown in Figs. 4: to 6 may alsobe obtained for that shown in Figs. 9 to 11.

In the form of device shown in Figs. 12 and 13 a single ratchet-wheel Fis used, engaged serz'atim by the upper and lower segments K and K,which are connected together by the arm K the links K and K and thebellerank lever K pivoted at 71:

It will be obvious from an inspection of Fig. 12 that a reciprocatingmotion of the hand-lever II will impart a continuous rotary motion tothe counter-shaft E, and hence to the set shaft 0, and thus the niceadjustment claimed for Figs. 4 to 6 and 9 to 11 may be obtained for thisconstruction.

In Figs. 9 to 11 I have shown an adjustable stop Q, which may be eitherin the form of a simple screw, as shown, or may be replaced by theadjustable stop shown in Figs. 1 and 4, or by any other suitableadjustable stop that may be adopted.

It will thus be seen that I provide a cheap, simple, effieient, andexceedingly exact method of operating and adjusting the motion of theknees, and thus of regulating the thickness of the board cut from thelog.

The various other advantages of the herein-described construction wouldreadily sug gest themselves to any one skilled in the art.

Having thus described my invention, what I claim, and desire to securebyLetters Patent of the United States, is-

1. In a sawmill-set-works organization, the combination with a main setshaft and rackand-pinion gearin g connecting said shaft with the knees,of receding springs placed under tension 011 said shaft and normallytending to withdraw said knees away from the sawline, a countershaftoutside of and parallel to said set shaft, a pinion loose thereon, withgearing connecting said pinion with said set shaft, a cl utch-couplingnormally connecting said pinion to said counter-shaft, means forreleasing said clutch-coupling, when desired, a pair of ratchet-wheelsfast on said countershaft, and segments provided with sprin g-operateddifferential pawls engaging in said ratcl1et-wheels, with means pivotedto said counter-shaft for operating said segments simultaneously inopposite directions, subline, a counter-shaft outside of and parallel tosaid set shaft, a pinion loose thereon, with gearing connecting saidpinion with said set shaft, a clutch-coupling normally connecting saidpinion to said counter-shaft, means for releasing said clutch-couplin g,when desired, a pair of ratchet-wheels fasten said countershaft,segments pivoted on said counter-shaft and provided with spring-operateddifferential pawls engaging in said ratchet-wheels, and ahand-lever alsopivoted to said co untcrshaft with connections adapted to operate saidsegments alternately and to cause the reciprocating motion of thehand-lever to develop a continuous rotary motion in said counter-shaft,substantially as and for the purposes described.

3. In a sawmill-set-works organization, the combination with aratchet-wheel and a pair of differential pawls, one of said pawls beingprovided with a rearwardly-projecting lug, of a spring interposedbetween the base of this lug and the top of the adjacent pawl, wherebyboth pawls are pressed toward the teeth of saidratchet-wheel,substantially as described.

4. In a sawmillset-works organization, the combination with the setshaft engaging the knees by rack-and-pinion gearing, a countershaft inrear of and parallel to said set shaft connected thereto bydisengageable gearing, and carrying a ratchet-wheel, of a pawl-carrieradapted to swing about said ratchetwheel, and provided with pawlsarranged in pairs, one of each pair of said pawls being provided with arearwardly-projecting lug and a spring interposed between the base ofthis lug and the top of the adjacent pawl, whereby both pawls arepressed down on said ratchet-wheel, substantially as described.

5. In a saWmill-set-works organization, the combination with aratchet-wheel of a pawl carrier adapted to swing about saidratchetwheel, a plurality of eccentric-pins set across saidpawl-carrier, a system of differential pawls pivoted on said pins, meansfor adj usting said pins a lever for actuating said pawlcarrier, and aquadrant, provided with set stops limiting the lever stroke in onedirection and an adjustable stop limiting it in the other direction,substantially as and for the purposes described.

In testimony whereof I aflix my signature in presence of two witnesses.

HENRY MODERMOTT. lVitnesses JOHN CHALMERS WILsoN, J. STEPHEN GINSTA.

